1. Field of the Invention
The present invention relates to a method and apparatus for supplying power to a central processing unit (CPU) of a computer.
2. Description of the Prior Art
Conventionally, a computer system incorporates a power supply, or an electrical/electronic circuit that supplies all operating voltages and current to the computer system. The basic function of the power supply is to convert the type of electrical power available at a wall socket to that which is usable by computer circuitry. The power supply in a conventional desktop computer system is designed to convert 120 volt, 60 Hz, AC current into something the computer system can use, specifically, both +5 and +12 volt DC current. Usually, the digital electronic components and circuits in the system (motherboard, adapter cards, and disk drive logic boards) use the +5 volt power, and the motors (disk drive motors and any fans) use the +12 volt power. A good, steady supply of both types of current must be provided by the power supply so that the system can operate properly.
A CPU is conventionally mounted on a motherboard and receives its power from the motherboard. Motherboards can draw anywhere from 4 to 15 amps or more of +5 volt power to run. First generation Pentium CPUs were fabricated with a processing die that was overly large and complicated to manufacture. The huge die and +5 volt power caused 66 MHz versions to consume up to an incredible 3.2 amps or 16 watts of power, resulting in a tremendous amount of heat, and problems in some computer systems that did not employ conservative design techniques. Often, the computer systems required a separate fan to blow on the CPUs to keep them cool.
Second and third generation Pentium CPUs, respectively code-named P54C and P55C, were developed to run on a variety of voltages. Several different versions of the Pentium processors run on 3.3 volts, 3.465 volts, as well as 2.9 volts, 2.5 volts, and even lower in the future. However, while several of the current motherboards support the 3.3 volt or 3.465 volt CPUs, few support the 2.9 volt versions. To flexibly accommodate the variety of CPU voltages, a CPU socket named Socket 7 was developed which requires the use of a voltage regulator module (VRM). The VRM is a small circuit board that contains all the voltage regulation circuitry used to drop the +5 volt power supply signal to the correct CPU voltage. Having a replaceable VRM plugged into a socket makes it easier to replace voltage regulators should they ever fail. The uncertainty over future CPU voltage and associated electrical requirements has resulted in a need to provide computer operators with the flexibility to ensure proper power delivery to present and future CPUs. Computer system configurations are known which are concerned with providing efficient and controllable power to computer systems.
U.S. Pat. No. 5,457,801, issued Oct. 10, 1995 to Norio Aihara, describes a power-saving system for a battery-powered computer which utilizes low power consumption elements such as CMOS elements and the ability to allow or stop power supply from a power supply. However, Aihara does not provide the ability to receive partial or complete central processing unit power directly from a power supply in accordance with the present invention.
U.S. Pat. No. 5,467,469, issued Nov. 14, 1995 to Toshimitsu Saito et al., describes a computer system configuration which provides a predetermined operation such as removal of a battery, an option board, a display, an external memory or the like from a computer main body while the computer system is running, followed by resume processing, whereby the hardware and software systems of the computer system are protected against damage, etc. Saito et al. do not provide the ability to receive partial or complete central processing unit power directly from a power supply in accordance with the present invention.
U.S. Pat. No. 5,521,854, issued May 28, 1996 to Tomohiko Kadowaki et al., describes a power saving control system for a computer system which provides the ability to control the supply of electric power from a power supply to respective functional portions of a computer system. Kadowaki et al. do not provide the ability to receive partial or complete central processing unit power directly from a power supply in accordance with the present invention.
U.S. Pat. No. 5,579,524, issued Nov. 26, 1996 to Dan Kikinis, describes a power supply system for a computer system that provides a plurality of power supplies for powering different elements in the computer system. However, Kikinis does not suggest providing partial or complete power directly from a power supply in accordance with the present invention.
U.S. Pat. No. 5,590,343, issued Dec. 31, 1996 to Michael L. Bolan et al., describes the use of a power switching device which is used to connect and disconnect a computer system's power supply unit from the power-line connection. Bolan et al.s do not suggest providing partial or complete power directly from a power supply in accordance with the present invention.
U.S. Pat. No. 5,606,713, issued Feb. 25, 1997 to Michael T. Wisor et al., describes a system management interrupt source employed in a computer system. Wisor et al. do not suggest providing partial or complete power directly from a power supply in accordance with the present invention.
U.S. Pat. No. 5,613,130, issued Mar. 18, 1997 to Yen-Chang G. Teng et al., describes a power control unit for delivering proper voltage to computer system elements. Teng et al. do not suggest providing partial or complete power directly from a power supply in accordance with the present invention.
German Patent Number 4,120,265, issued on Jan. 9, 1992 to Toshiyuki Matsubara, describes a manner of operating a central processing unit with signals from a generator which can be interrupted. Matsubara does not suggest providing partial or complete power directly from a power supply in accordance with the present invention.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.